The way I think about it is that there are a number of conditions that can cause serious depression, some of which are known and have a straight-forward treatme

The way I think about it is that there are a number of conditions that can cause serious depression, some of which are known and have a straight-forward treatment, for instance, thyroid and hormonal issues, certain sleeping disorders, and certain nutrition issues. If the cause of the mental issues is unknown, you're left with treating the symptoms, which is certainly better than nothing, but often inexact and trial and error. Thus it makes sense to knock out any probable known causes when starting treatment before assuming an unknown cause. My personal experience was when I was first diagnosed is that I had my vitamin levels checked, thyroid checked, had some sleep labs, and everyone recommended losing weight and exercise.